A wide range of audio processing systems exist which capture audio signals from one or microphones and undertake one or more signal processing tasks on the microphone signal(s) for various purposes. For example, headsets are a popular way for a user to listen to music or audio privately, or to make a hands-free phone call, or to deliver voice commands to a voice recognition system. A wide range of headset form factors, i.e. types of headsets, are available, including earbuds, on-ear (supraaural), over-ear (circumaural), neckband, pendant, and the like, each of which provide one or microphones at various locations on the device in order to capture audio signals such as the user's speech or environmental noise.
There are numerous audio processing algorithms which depend heavily on the unimpeded exposure of microphones to the acoustic environment. For example, devices with multiple sensors or microphones may contain algorithms to process the multiple sources of data, and in such algorithms it is usually assumed that the measurements from each sensor are of equal quality. However, the performance of many such algorithms is markedly degraded if any of the microphones is partly or wholly blocked, obstructed or occluded. A blocked microphone may for example be caused by the user touching or covering the microphone port, or by the ingress of dirt, clothing, hair or the like into the microphone port. A microphone may be blocked only briefly such as when touched by the user, or may be blocked for a long period such as when caused by dirt ingress. The performance of the numerous processing algorithms which may act upon the microphone signal can be heavily influenced or degraded by a blocked microphone.
Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
In this specification, a statement that an element may be “at least one of” a list of options is to be understood that the element may be any one of the listed options, or may be any combination of two or more of the listed options.